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super.c
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// SPDX-License-Identifier: GPL-2.0
/*
* Simple file system for zoned block devices exposing zones as files.
*
* Copyright (C) 2019 Western Digital Corporation or its affiliates.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/magic.h>
#include <linux/iomap.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/statfs.h>
#include <linux/writeback.h>
#include <linux/quotaops.h>
#include <linux/seq_file.h>
#include <linux/parser.h>
#include <linux/uio.h>
#include <linux/mman.h>
#include <linux/sched/mm.h>
#include <linux/crc32.h>
#include "zonefs.h"
static int zonefs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned int flags, struct iomap *iomap,
struct iomap *srcmap)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct super_block *sb = inode->i_sb;
loff_t isize;
/* All I/Os should always be within the file maximum size */
if (WARN_ON_ONCE(offset + length > zi->i_max_size))
return -EIO;
/*
* Sequential zones can only accept direct writes. This is already
* checked when writes are issued, so warn if we see a page writeback
* operation.
*/
if (WARN_ON_ONCE(zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
(flags & IOMAP_WRITE) && !(flags & IOMAP_DIRECT)))
return -EIO;
/*
* For conventional zones, all blocks are always mapped. For sequential
* zones, all blocks after always mapped below the inode size (zone
* write pointer) and unwriten beyond.
*/
mutex_lock(&zi->i_truncate_mutex);
isize = i_size_read(inode);
if (offset >= isize)
iomap->type = IOMAP_UNWRITTEN;
else
iomap->type = IOMAP_MAPPED;
if (flags & IOMAP_WRITE)
length = zi->i_max_size - offset;
else
length = min(length, isize - offset);
mutex_unlock(&zi->i_truncate_mutex);
iomap->offset = ALIGN_DOWN(offset, sb->s_blocksize);
iomap->length = ALIGN(offset + length, sb->s_blocksize) - iomap->offset;
iomap->bdev = inode->i_sb->s_bdev;
iomap->addr = (zi->i_zsector << SECTOR_SHIFT) + iomap->offset;
return 0;
}
static const struct iomap_ops zonefs_iomap_ops = {
.iomap_begin = zonefs_iomap_begin,
};
static int zonefs_readpage(struct file *unused, struct page *page)
{
return iomap_readpage(page, &zonefs_iomap_ops);
}
static int zonefs_readpages(struct file *unused, struct address_space *mapping,
struct list_head *pages, unsigned int nr_pages)
{
return iomap_readpages(mapping, pages, nr_pages, &zonefs_iomap_ops);
}
/*
* Map blocks for page writeback. This is used only on conventional zone files,
* which implies that the page range can only be within the fixed inode size.
*/
static int zonefs_map_blocks(struct iomap_writepage_ctx *wpc,
struct inode *inode, loff_t offset)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
if (WARN_ON_ONCE(zi->i_ztype != ZONEFS_ZTYPE_CNV))
return -EIO;
if (WARN_ON_ONCE(offset >= i_size_read(inode)))
return -EIO;
/* If the mapping is already OK, nothing needs to be done */
if (offset >= wpc->iomap.offset &&
offset < wpc->iomap.offset + wpc->iomap.length)
return 0;
return zonefs_iomap_begin(inode, offset, zi->i_max_size - offset,
IOMAP_WRITE, &wpc->iomap, NULL);
}
static const struct iomap_writeback_ops zonefs_writeback_ops = {
.map_blocks = zonefs_map_blocks,
};
static int zonefs_writepage(struct page *page, struct writeback_control *wbc)
{
struct iomap_writepage_ctx wpc = { };
return iomap_writepage(page, wbc, &wpc, &zonefs_writeback_ops);
}
static int zonefs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct iomap_writepage_ctx wpc = { };
return iomap_writepages(mapping, wbc, &wpc, &zonefs_writeback_ops);
}
static const struct address_space_operations zonefs_file_aops = {
.readpage = zonefs_readpage,
.readpages = zonefs_readpages,
.writepage = zonefs_writepage,
.writepages = zonefs_writepages,
.set_page_dirty = iomap_set_page_dirty,
.releasepage = iomap_releasepage,
.invalidatepage = iomap_invalidatepage,
.migratepage = iomap_migrate_page,
.is_partially_uptodate = iomap_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,
.direct_IO = noop_direct_IO,
};
static void zonefs_update_stats(struct inode *inode, loff_t new_isize)
{
struct super_block *sb = inode->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
loff_t old_isize = i_size_read(inode);
loff_t nr_blocks;
if (new_isize == old_isize)
return;
spin_lock(&sbi->s_lock);
/*
* This may be called for an update after an IO error.
* So beware of the values seen.
*/
if (new_isize < old_isize) {
nr_blocks = (old_isize - new_isize) >> sb->s_blocksize_bits;
if (sbi->s_used_blocks > nr_blocks)
sbi->s_used_blocks -= nr_blocks;
else
sbi->s_used_blocks = 0;
} else {
sbi->s_used_blocks +=
(new_isize - old_isize) >> sb->s_blocksize_bits;
if (sbi->s_used_blocks > sbi->s_blocks)
sbi->s_used_blocks = sbi->s_blocks;
}
spin_unlock(&sbi->s_lock);
}
/*
* Check a zone condition and adjust its file inode access permissions for
* offline and readonly zones. Return the inode size corresponding to the
* amount of readable data in the zone.
*/
static loff_t zonefs_check_zone_condition(struct inode *inode,
struct blk_zone *zone, bool warn,
bool mount)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
switch (zone->cond) {
case BLK_ZONE_COND_OFFLINE:
/*
* Dead zone: make the inode immutable, disable all accesses
* and set the file size to 0 (zone wp set to zone start).
*/
if (warn)
zonefs_warn(inode->i_sb, "inode %lu: offline zone\n",
inode->i_ino);
inode->i_flags |= S_IMMUTABLE;
inode->i_mode &= ~0777;
zone->wp = zone->start;
return 0;
case BLK_ZONE_COND_READONLY:
/*
* The write pointer of read-only zones is invalid. If such a
* zone is found during mount, the file size cannot be retrieved
* so we treat the zone as offline (mount == true case).
* Otherwise, keep the file size as it was when last updated
* so that the user can recover data. In both cases, writes are
* always disabled for the zone.
*/
if (warn)
zonefs_warn(inode->i_sb, "inode %lu: read-only zone\n",
inode->i_ino);
inode->i_flags |= S_IMMUTABLE;
if (mount) {
zone->cond = BLK_ZONE_COND_OFFLINE;
inode->i_mode &= ~0777;
zone->wp = zone->start;
return 0;
}
inode->i_mode &= ~0222;
return i_size_read(inode);
default:
if (zi->i_ztype == ZONEFS_ZTYPE_CNV)
return zi->i_max_size;
return (zone->wp - zone->start) << SECTOR_SHIFT;
}
}
struct zonefs_ioerr_data {
struct inode *inode;
bool write;
};
static int zonefs_io_error_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
struct zonefs_ioerr_data *err = data;
struct inode *inode = err->inode;
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct super_block *sb = inode->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
loff_t isize, data_size;
/*
* Check the zone condition: if the zone is not "bad" (offline or
* read-only), read errors are simply signaled to the IO issuer as long
* as there is no inconsistency between the inode size and the amount of
* data writen in the zone (data_size).
*/
data_size = zonefs_check_zone_condition(inode, zone, true, false);
isize = i_size_read(inode);
if (zone->cond != BLK_ZONE_COND_OFFLINE &&
zone->cond != BLK_ZONE_COND_READONLY &&
!err->write && isize == data_size)
return 0;
/*
* At this point, we detected either a bad zone or an inconsistency
* between the inode size and the amount of data written in the zone.
* For the latter case, the cause may be a write IO error or an external
* action on the device. Two error patterns exist:
* 1) The inode size is lower than the amount of data in the zone:
* a write operation partially failed and data was writen at the end
* of the file. This can happen in the case of a large direct IO
* needing several BIOs and/or write requests to be processed.
* 2) The inode size is larger than the amount of data in the zone:
* this can happen with a deferred write error with the use of the
* device side write cache after getting successful write IO
* completions. Other possibilities are (a) an external corruption,
* e.g. an application reset the zone directly, or (b) the device
* has a serious problem (e.g. firmware bug).
*
* In all cases, warn about inode size inconsistency and handle the
* IO error according to the zone condition and to the mount options.
*/
if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && isize != data_size)
zonefs_warn(sb, "inode %lu: invalid size %lld (should be %lld)\n",
inode->i_ino, isize, data_size);
/*
* First handle bad zones signaled by hardware. The mount options
* errors=zone-ro and errors=zone-offline result in changing the
* zone condition to read-only and offline respectively, as if the
* condition was signaled by the hardware.
*/
if (zone->cond == BLK_ZONE_COND_OFFLINE ||
sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL) {
zonefs_warn(sb, "inode %lu: read/write access disabled\n",
inode->i_ino);
if (zone->cond != BLK_ZONE_COND_OFFLINE) {
zone->cond = BLK_ZONE_COND_OFFLINE;
data_size = zonefs_check_zone_condition(inode, zone,
false, false);
}
} else if (zone->cond == BLK_ZONE_COND_READONLY ||
sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO) {
zonefs_warn(sb, "inode %lu: write access disabled\n",
inode->i_ino);
if (zone->cond != BLK_ZONE_COND_READONLY) {
zone->cond = BLK_ZONE_COND_READONLY;
data_size = zonefs_check_zone_condition(inode, zone,
false, false);
}
}
/*
* If error=remount-ro was specified, any error result in remounting
* the volume as read-only.
*/
if ((sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO) && !sb_rdonly(sb)) {
zonefs_warn(sb, "remounting filesystem read-only\n");
sb->s_flags |= SB_RDONLY;
}
/*
* Update block usage stats and the inode size to prevent access to
* invalid data.
*/
zonefs_update_stats(inode, data_size);
i_size_write(inode, data_size);
zi->i_wpoffset = data_size;
return 0;
}
/*
* When an file IO error occurs, check the file zone to see if there is a change
* in the zone condition (e.g. offline or read-only). For a failed write to a
* sequential zone, the zone write pointer position must also be checked to
* eventually correct the file size and zonefs inode write pointer offset
* (which can be out of sync with the drive due to partial write failures).
*/
static void zonefs_io_error(struct inode *inode, bool write)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct super_block *sb = inode->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
unsigned int noio_flag;
unsigned int nr_zones =
zi->i_max_size >> (sbi->s_zone_sectors_shift + SECTOR_SHIFT);
struct zonefs_ioerr_data err = {
.inode = inode,
.write = write,
};
int ret;
mutex_lock(&zi->i_truncate_mutex);
/*
* Memory allocations in blkdev_report_zones() can trigger a memory
* reclaim which may in turn cause a recursion into zonefs as well as
* struct request allocations for the same device. The former case may
* end up in a deadlock on the inode truncate mutex, while the latter
* may prevent IO forward progress. Executing the report zones under
* the GFP_NOIO context avoids both problems.
*/
noio_flag = memalloc_noio_save();
ret = blkdev_report_zones(sb->s_bdev, zi->i_zsector, nr_zones,
zonefs_io_error_cb, &err);
if (ret != nr_zones)
zonefs_err(sb, "Get inode %lu zone information failed %d\n",
inode->i_ino, ret);
memalloc_noio_restore(noio_flag);
mutex_unlock(&zi->i_truncate_mutex);
}
static int zonefs_file_truncate(struct inode *inode, loff_t isize)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
loff_t old_isize;
enum req_opf op;
int ret = 0;
/*
* Only sequential zone files can be truncated and truncation is allowed
* only down to a 0 size, which is equivalent to a zone reset, and to
* the maximum file size, which is equivalent to a zone finish.
*/
if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
return -EPERM;
if (!isize)
op = REQ_OP_ZONE_RESET;
else if (isize == zi->i_max_size)
op = REQ_OP_ZONE_FINISH;
else
return -EPERM;
inode_dio_wait(inode);
/* Serialize against page faults */
down_write(&zi->i_mmap_sem);
/* Serialize against zonefs_iomap_begin() */
mutex_lock(&zi->i_truncate_mutex);
old_isize = i_size_read(inode);
if (isize == old_isize)
goto unlock;
ret = blkdev_zone_mgmt(inode->i_sb->s_bdev, op, zi->i_zsector,
zi->i_max_size >> SECTOR_SHIFT, GFP_NOFS);
if (ret) {
zonefs_err(inode->i_sb,
"Zone management operation at %llu failed %d",
zi->i_zsector, ret);
goto unlock;
}
zonefs_update_stats(inode, isize);
truncate_setsize(inode, isize);
zi->i_wpoffset = isize;
unlock:
mutex_unlock(&zi->i_truncate_mutex);
up_write(&zi->i_mmap_sem);
return ret;
}
static int zonefs_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
struct inode *inode = d_inode(dentry);
int ret;
if (unlikely(IS_IMMUTABLE(inode)))
return -EPERM;
ret = setattr_prepare(dentry, iattr);
if (ret)
return ret;
/*
* Since files and directories cannot be created nor deleted, do not
* allow setting any write attributes on the sub-directories grouping
* files by zone type.
*/
if ((iattr->ia_valid & ATTR_MODE) && S_ISDIR(inode->i_mode) &&
(iattr->ia_mode & 0222))
return -EPERM;
if (((iattr->ia_valid & ATTR_UID) &&
!uid_eq(iattr->ia_uid, inode->i_uid)) ||
((iattr->ia_valid & ATTR_GID) &&
!gid_eq(iattr->ia_gid, inode->i_gid))) {
ret = dquot_transfer(inode, iattr);
if (ret)
return ret;
}
if (iattr->ia_valid & ATTR_SIZE) {
ret = zonefs_file_truncate(inode, iattr->ia_size);
if (ret)
return ret;
}
setattr_copy(inode, iattr);
return 0;
}
static const struct inode_operations zonefs_file_inode_operations = {
.setattr = zonefs_inode_setattr,
};
static int zonefs_file_fsync(struct file *file, loff_t start, loff_t end,
int datasync)
{
struct inode *inode = file_inode(file);
int ret = 0;
if (unlikely(IS_IMMUTABLE(inode)))
return -EPERM;
/*
* Since only direct writes are allowed in sequential files, page cache
* flush is needed only for conventional zone files.
*/
if (ZONEFS_I(inode)->i_ztype == ZONEFS_ZTYPE_CNV)
ret = file_write_and_wait_range(file, start, end);
if (!ret)
ret = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
if (ret)
zonefs_io_error(inode, true);
return ret;
}
static vm_fault_t zonefs_filemap_fault(struct vm_fault *vmf)
{
struct zonefs_inode_info *zi = ZONEFS_I(file_inode(vmf->vma->vm_file));
vm_fault_t ret;
down_read(&zi->i_mmap_sem);
ret = filemap_fault(vmf);
up_read(&zi->i_mmap_sem);
return ret;
}
static vm_fault_t zonefs_filemap_page_mkwrite(struct vm_fault *vmf)
{
struct inode *inode = file_inode(vmf->vma->vm_file);
struct zonefs_inode_info *zi = ZONEFS_I(inode);
vm_fault_t ret;
if (unlikely(IS_IMMUTABLE(inode)))
return VM_FAULT_SIGBUS;
/*
* Sanity check: only conventional zone files can have shared
* writeable mappings.
*/
if (WARN_ON_ONCE(zi->i_ztype != ZONEFS_ZTYPE_CNV))
return VM_FAULT_NOPAGE;
sb_start_pagefault(inode->i_sb);
file_update_time(vmf->vma->vm_file);
/* Serialize against truncates */
down_read(&zi->i_mmap_sem);
ret = iomap_page_mkwrite(vmf, &zonefs_iomap_ops);
up_read(&zi->i_mmap_sem);
sb_end_pagefault(inode->i_sb);
return ret;
}
static const struct vm_operations_struct zonefs_file_vm_ops = {
.fault = zonefs_filemap_fault,
.map_pages = filemap_map_pages,
.page_mkwrite = zonefs_filemap_page_mkwrite,
};
static int zonefs_file_mmap(struct file *file, struct vm_area_struct *vma)
{
/*
* Conventional zones accept random writes, so their files can support
* shared writable mappings. For sequential zone files, only read
* mappings are possible since there are no guarantees for write
* ordering between msync() and page cache writeback.
*/
if (ZONEFS_I(file_inode(file))->i_ztype == ZONEFS_ZTYPE_SEQ &&
(vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
return -EINVAL;
file_accessed(file);
vma->vm_ops = &zonefs_file_vm_ops;
return 0;
}
static loff_t zonefs_file_llseek(struct file *file, loff_t offset, int whence)
{
loff_t isize = i_size_read(file_inode(file));
/*
* Seeks are limited to below the zone size for conventional zones
* and below the zone write pointer for sequential zones. In both
* cases, this limit is the inode size.
*/
return generic_file_llseek_size(file, offset, whence, isize, isize);
}
static int zonefs_file_write_dio_end_io(struct kiocb *iocb, ssize_t size,
int error, unsigned int flags)
{
struct inode *inode = file_inode(iocb->ki_filp);
struct zonefs_inode_info *zi = ZONEFS_I(inode);
if (error) {
zonefs_io_error(inode, true);
return error;
}
if (size && zi->i_ztype != ZONEFS_ZTYPE_CNV) {
/*
* Note that we may be seeing completions out of order,
* but that is not a problem since a write completed
* successfully necessarily means that all preceding writes
* were also successful. So we can safely increase the inode
* size to the write end location.
*/
mutex_lock(&zi->i_truncate_mutex);
if (i_size_read(inode) < iocb->ki_pos + size) {
zonefs_update_stats(inode, iocb->ki_pos + size);
i_size_write(inode, iocb->ki_pos + size);
}
mutex_unlock(&zi->i_truncate_mutex);
}
return 0;
}
static const struct iomap_dio_ops zonefs_write_dio_ops = {
.end_io = zonefs_file_write_dio_end_io,
};
/*
* Handle direct writes. For sequential zone files, this is the only possible
* write path. For these files, check that the user is issuing writes
* sequentially from the end of the file. This code assumes that the block layer
* delivers write requests to the device in sequential order. This is always the
* case if a block IO scheduler implementing the ELEVATOR_F_ZBD_SEQ_WRITE
* elevator feature is being used (e.g. mq-deadline). The block layer always
* automatically select such an elevator for zoned block devices during the
* device initialization.
*/
static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
{
struct inode *inode = file_inode(iocb->ki_filp);
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct super_block *sb = inode->i_sb;
size_t count;
ssize_t ret;
/*
* For async direct IOs to sequential zone files, refuse IOCB_NOWAIT
* as this can cause write reordering (e.g. the first aio gets EAGAIN
* on the inode lock but the second goes through but is now unaligned).
*/
if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && !is_sync_kiocb(iocb) &&
(iocb->ki_flags & IOCB_NOWAIT))
return -EOPNOTSUPP;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!inode_trylock(inode))
return -EAGAIN;
} else {
inode_lock(inode);
}
ret = generic_write_checks(iocb, from);
if (ret <= 0)
goto inode_unlock;
iov_iter_truncate(from, zi->i_max_size - iocb->ki_pos);
count = iov_iter_count(from);
if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
ret = -EINVAL;
goto inode_unlock;
}
/* Enforce sequential writes (append only) in sequential zones */
mutex_lock(&zi->i_truncate_mutex);
if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && iocb->ki_pos != zi->i_wpoffset) {
mutex_unlock(&zi->i_truncate_mutex);
ret = -EINVAL;
goto inode_unlock;
}
mutex_unlock(&zi->i_truncate_mutex);
ret = iomap_dio_rw(iocb, from, &zonefs_iomap_ops,
&zonefs_write_dio_ops, is_sync_kiocb(iocb));
if (zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
(ret > 0 || ret == -EIOCBQUEUED)) {
if (ret > 0)
count = ret;
mutex_lock(&zi->i_truncate_mutex);
zi->i_wpoffset += count;
mutex_unlock(&zi->i_truncate_mutex);
}
inode_unlock:
inode_unlock(inode);
return ret;
}
static ssize_t zonefs_file_buffered_write(struct kiocb *iocb,
struct iov_iter *from)
{
struct inode *inode = file_inode(iocb->ki_filp);
struct zonefs_inode_info *zi = ZONEFS_I(inode);
ssize_t ret;
/*
* Direct IO writes are mandatory for sequential zone files so that the
* write IO issuing order is preserved.
*/
if (zi->i_ztype != ZONEFS_ZTYPE_CNV)
return -EIO;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!inode_trylock(inode))
return -EAGAIN;
} else {
inode_lock(inode);
}
ret = generic_write_checks(iocb, from);
if (ret <= 0)
goto inode_unlock;
iov_iter_truncate(from, zi->i_max_size - iocb->ki_pos);
ret = iomap_file_buffered_write(iocb, from, &zonefs_iomap_ops);
if (ret > 0)
iocb->ki_pos += ret;
else if (ret == -EIO)
zonefs_io_error(inode, true);
inode_unlock:
inode_unlock(inode);
if (ret > 0)
ret = generic_write_sync(iocb, ret);
return ret;
}
static ssize_t zonefs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct inode *inode = file_inode(iocb->ki_filp);
if (unlikely(IS_IMMUTABLE(inode)))
return -EPERM;
if (sb_rdonly(inode->i_sb))
return -EROFS;
/* Write operations beyond the zone size are not allowed */
if (iocb->ki_pos >= ZONEFS_I(inode)->i_max_size)
return -EFBIG;
if (iocb->ki_flags & IOCB_DIRECT)
return zonefs_file_dio_write(iocb, from);
return zonefs_file_buffered_write(iocb, from);
}
static int zonefs_file_read_dio_end_io(struct kiocb *iocb, ssize_t size,
int error, unsigned int flags)
{
if (error) {
zonefs_io_error(file_inode(iocb->ki_filp), false);
return error;
}
return 0;
}
static const struct iomap_dio_ops zonefs_read_dio_ops = {
.end_io = zonefs_file_read_dio_end_io,
};
static ssize_t zonefs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct inode *inode = file_inode(iocb->ki_filp);
struct zonefs_inode_info *zi = ZONEFS_I(inode);
struct super_block *sb = inode->i_sb;
loff_t isize;
ssize_t ret;
/* Offline zones cannot be read */
if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777)))
return -EPERM;
if (iocb->ki_pos >= zi->i_max_size)
return 0;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!inode_trylock_shared(inode))
return -EAGAIN;
} else {
inode_lock_shared(inode);
}
/* Limit read operations to written data */
mutex_lock(&zi->i_truncate_mutex);
isize = i_size_read(inode);
if (iocb->ki_pos >= isize) {
mutex_unlock(&zi->i_truncate_mutex);
ret = 0;
goto inode_unlock;
}
iov_iter_truncate(to, isize - iocb->ki_pos);
mutex_unlock(&zi->i_truncate_mutex);
if (iocb->ki_flags & IOCB_DIRECT) {
size_t count = iov_iter_count(to);
if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
ret = -EINVAL;
goto inode_unlock;
}
file_accessed(iocb->ki_filp);
ret = iomap_dio_rw(iocb, to, &zonefs_iomap_ops,
&zonefs_read_dio_ops, is_sync_kiocb(iocb));
} else {
ret = generic_file_read_iter(iocb, to);
if (ret == -EIO)
zonefs_io_error(inode, false);
}
inode_unlock:
inode_unlock_shared(inode);
return ret;
}
static const struct file_operations zonefs_file_operations = {
.open = generic_file_open,
.fsync = zonefs_file_fsync,
.mmap = zonefs_file_mmap,
.llseek = zonefs_file_llseek,
.read_iter = zonefs_file_read_iter,
.write_iter = zonefs_file_write_iter,
.splice_read = generic_file_splice_read,
.splice_write = iter_file_splice_write,
.iopoll = iomap_dio_iopoll,
};
static struct kmem_cache *zonefs_inode_cachep;
static struct inode *zonefs_alloc_inode(struct super_block *sb)
{
struct zonefs_inode_info *zi;
zi = kmem_cache_alloc(zonefs_inode_cachep, GFP_KERNEL);
if (!zi)
return NULL;
inode_init_once(&zi->i_vnode);
mutex_init(&zi->i_truncate_mutex);
init_rwsem(&zi->i_mmap_sem);
return &zi->i_vnode;
}
static void zonefs_free_inode(struct inode *inode)
{
kmem_cache_free(zonefs_inode_cachep, ZONEFS_I(inode));
}
/*
* File system stat.
*/
static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
enum zonefs_ztype t;
u64 fsid;
buf->f_type = ZONEFS_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_namelen = ZONEFS_NAME_MAX;
spin_lock(&sbi->s_lock);
buf->f_blocks = sbi->s_blocks;
if (WARN_ON(sbi->s_used_blocks > sbi->s_blocks))
buf->f_bfree = 0;
else
buf->f_bfree = buf->f_blocks - sbi->s_used_blocks;
buf->f_bavail = buf->f_bfree;
for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {
if (sbi->s_nr_files[t])
buf->f_files += sbi->s_nr_files[t] + 1;
}
buf->f_ffree = 0;
spin_unlock(&sbi->s_lock);
fsid = le64_to_cpup((void *)sbi->s_uuid.b) ^
le64_to_cpup((void *)sbi->s_uuid.b + sizeof(u64));
buf->f_fsid.val[0] = (u32)fsid;
buf->f_fsid.val[1] = (u32)(fsid >> 32);
return 0;
}
enum {
Opt_errors_ro, Opt_errors_zro, Opt_errors_zol, Opt_errors_repair,
Opt_err,
};
static const match_table_t tokens = {
{ Opt_errors_ro, "errors=remount-ro"},
{ Opt_errors_zro, "errors=zone-ro"},
{ Opt_errors_zol, "errors=zone-offline"},
{ Opt_errors_repair, "errors=repair"},
{ Opt_err, NULL}
};
static int zonefs_parse_options(struct super_block *sb, char *options)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
substring_t args[MAX_OPT_ARGS];
char *p;
if (!options)
return 0;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_errors_ro:
sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_RO;
break;
case Opt_errors_zro:
sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZRO;
break;
case Opt_errors_zol:
sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZOL;
break;
case Opt_errors_repair:
sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_REPAIR;
break;
default:
return -EINVAL;
}
}
return 0;
}
static int zonefs_show_options(struct seq_file *seq, struct dentry *root)
{
struct zonefs_sb_info *sbi = ZONEFS_SB(root->d_sb);
if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO)
seq_puts(seq, ",errors=remount-ro");
if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO)
seq_puts(seq, ",errors=zone-ro");
if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL)
seq_puts(seq, ",errors=zone-offline");
if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_REPAIR)
seq_puts(seq, ",errors=repair");
return 0;
}
static int zonefs_remount(struct super_block *sb, int *flags, char *data)
{
sync_filesystem(sb);
return zonefs_parse_options(sb, data);
}
static const struct super_operations zonefs_sops = {
.alloc_inode = zonefs_alloc_inode,
.free_inode = zonefs_free_inode,
.statfs = zonefs_statfs,
.remount_fs = zonefs_remount,
.show_options = zonefs_show_options,
};
static const struct inode_operations zonefs_dir_inode_operations = {
.lookup = simple_lookup,
.setattr = zonefs_inode_setattr,
};
static void zonefs_init_dir_inode(struct inode *parent, struct inode *inode,
enum zonefs_ztype type)
{
struct super_block *sb = parent->i_sb;
inode->i_ino = blkdev_nr_zones(sb->s_bdev->bd_disk) + type + 1;
inode_init_owner(inode, parent, S_IFDIR | 0555);
inode->i_op = &zonefs_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
set_nlink(inode, 2);
inc_nlink(parent);
}
static void zonefs_init_file_inode(struct inode *inode, struct blk_zone *zone,
enum zonefs_ztype type)
{
struct super_block *sb = inode->i_sb;
struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
struct zonefs_inode_info *zi = ZONEFS_I(inode);
inode->i_ino = zone->start >> sbi->s_zone_sectors_shift;
inode->i_mode = S_IFREG | sbi->s_perm;
zi->i_ztype = type;
zi->i_zsector = zone->start;
zi->i_max_size = min_t(loff_t, MAX_LFS_FILESIZE,
zone->len << SECTOR_SHIFT);
zi->i_wpoffset = zonefs_check_zone_condition(inode, zone, true, true);
inode->i_uid = sbi->s_uid;
inode->i_gid = sbi->s_gid;
inode->i_size = zi->i_wpoffset;
inode->i_blocks = zone->len;
inode->i_op = &zonefs_file_inode_operations;
inode->i_fop = &zonefs_file_operations;